Psychologist in a Pocket: Lexicon Development and Content Validation of a Mobile-Based App for Depression Screening

Area of Science:

• Psychology
• Mobile Health
• Natural Language Processing

Background:

• Language use offers insights into mental health, psychological conditions, and personal characteristics.
• Mobile technology enables ecological momentary assessment (EMA) for real-time behavioral capture.
• Integrating mobile tech into mental healthcare can enhance initial assessments, particularly for mood disturbances like depression.

Purpose of the Study:

• To generate and develop a specialized lexicon for detecting depression via text input in mobile applications.
• To perform content validation as an initial assessment of the developed lexicon for the Psychologist in a Pocket (PiaP) app.

Main Methods:

• Lexicon development involved gathering depression-related terms from DSM-5 and ICD-10 criteria.
• Data sources included Filipino college student focus groups, mental health professional interviews, and established depression scales.
• Content validation ensured keywords met a Content Validity Ratio (CVR) of 0.75 or higher.

Main Results:

• The lexicon development phase identified 13 categories of depressive symptoms.
• A draft lexicon included 1762 main keywords, 9655 derivatives, and 823,869 spelling variations.
• The test-run version comprises 1498 main keywords, 8911 derivatives, and 783,140 spelling variations, with a high overall CVI of 0.90.

Conclusions:

• The generated depression lexicon is extensive and culturally relevant for a specific age group.
• The lexicon captures characteristic expressions of depression and related constructs.
• The content-validated mobile health app PiaP shows potential for effective early detection of depressive symptoms.